Thursday, November 5, 2009

Surviving Disaster: Avalanche

It took me a while to catch up with this episode of Surviving Disaster (apparently the show is available online for a week after original broadcast then taken down for a month then put up after the month is over). Here's the high points from the Surviving Disaster-Avalanche show which can be found here:

Scenario: a group of friends head out to the mountains to go skiing and snowboarding in the out-of-bounds area.

There are 500 winter resorts in North America which are visited by 60 million people annually.

If you choose to ski in out-of-bounds areas always carry an avalanche beacon, probe, and snow shovel and ALWAYS tell someone where you intend to be skiing.

In the winter back country there are a number of dangers including: white outs, blizzards, high temperature fluctuations, wildlife, and avalanche.

If you find yourself in a white-out, stop immediately and gather your group together. Always stay together as a group because you have a better chance of survival this way. Don't try to travel during a white-out as you will become lost immediately.

During a blizzard or white out, remember that rescue teams will not be able to be out looking for you until the weather improves.

During the white-out, one of the group was injured because he boarded off the side of a cliff.

First priority, check the victim's condition. Have the victim move his feet and squeeze your hands to check for spinal injuries. Don't move a person with neck or back injuries unless absolutely necessary.

The victim had an open leg fracture. Normally don't try to realign an open fracture if there is the possibility of rescue soon. If you won't be rescued for a while you will need to try to realign the fracture to prevent the bone for drying out an infection from setting in. Stop the bleeding with direct pressure on a cloth put above the break--don't touch the exposed bone. Have people hold the victim down while one person slowly pulls the ankle in an effort to realign the bone. If you hit resistance, don't continue as this could sever nerves or an artery. Use ski poles and straps from backpacks to immobilize the leg by tying the leg above and below the break to the ski poles.

Use a snowboard as a sled to transport the patient. Drag the patient head first on the sled down the hill. One person will lead the group looking for crevasses, two people will drag the patient by the sleeves of his jacket and a third will keep hold of the back of the sled with a rope to control speed

Try to make it to the tree line as this will provide better shelter from the wind.

Wind chill, cold temperatures, and wet clothes all increase the chance of hypothermia.

Before nightfall you will need to find shelter. In this case the group didn't make it to the tree line and needed to build a snow cave. You will be 50 degrees warmer in a snow cave than out in the elements.

To build a snow cave, look for a major accumulation of snow that is downwind. Dig an entrance hole up into the snow then shovel out the snow from the cave leaving a dome-shaped ceiling to prevent collapse. Use the snow you removed to create a sleep shelf above the entrance hole. Work fast but do not sweat when making the cave or you could become hypothermic. Rotate people working on the cave every two minutes.

Once the cave is built, get everyone into the cave. Have everyone stay on the sleep shelf where the warm air will stay; cooler air will drop down and out the entrance hole.

The injured person has the greatest risk of hypothermia as he is not moving. If he is shivering, that's good, if he isn't shivering, that's not good.

Put the victim on the sleep shelf and elevate his leg on packs. Have him count backwards from 100 to check his mental acuity. Check his clothing, if they are wet remove them. If his clothes are dry, wrap his sleeves together to conserve heat. Try to feed him.

Make the victim a "hot water bottle" by having someone urinate into a bottle then put the bottle next to his groin, armpit, or under his neck.

Never give a hypothermic person alcohol as this exacerbates the problem.

Keep the group attentive over night by giving each a job (one watch the patient, one keep entrance clear, etc) then switch jobs every hour.

If the weather has improved by morning, the group will need to go for help. The chance of rescue decreases by 1/3 each day.

Leave the slowest person behind with the patient and the rest of the group should go for help. It will take 10 times longer to find help if you are bringing along the injured person.

It was noted that in a survival situation, you want to take the emotion out of your decisions in order to make wise choices. It was also noted that in most survival situations, you are responsible for yourself and often you can't wait for people to come and rescue you.

The chance of avalanche is greater the first 24 to 48 hours after a heavy snowfall.

Use the urine from the bottle to mark a circle around the cave, this will be a good signal for helicopter rescuers to see.

When the group got to the treeline, they took off their skis and snowboards. Snowshoes are the best way to travel over deep snow. They made snowshoes by gathering branches and tying them onto their boots with bungee cords and ties; one bungee cord was wrapped around the back of the ankle and tied on to the ties that were holding the branches to their boots to keep the "snow shoe" in place.

When the group was walking, they came upon an animal carcass. You can eat the brains and bone marrow for protein and use the fat to help start a fire.

The group next came upon a bear. Grizzly bears have a round face and hump on its back, black bears have no hump and pointy ears. You can play dead if a grizzly bear attacks ansd it will leave you alone but not with a black bear which will "tear you apart out of curiosity". Never run from a bear or it will chase you. Try to act submissive with a grizzly bear, don't look it in the eye, and back away slowly from the bear as a group.

One person ran from the bear, the bear chased him, he dropped to the ground and played dead, and the rest of the group scarred the bear away by making a lot of noise.

To cross an open area, take off the snow shoes and put on skis/snowboards. Turn on your avalanche beacon, tighten backpacks, and zip your coat up to the top (if you are caught in an avalanche, you don't want cold snow inside your jacket).

Note that open areas with steep grades and heavy snow are prime avalanche locations.

The group should cross the open area one at a time. The person crossing should try to stay near trees and rock outcroppings while the rest of the group should watch him cross (this way they can see where to start searching for him if he is caught in an avalanche).

You will hear a "whoof" sound when snow is adjusting or settling before an avalanche.

If you see an avalanche coming, try to ski to the side of it, not in front of it. If you get caught in the avalanche, cup your hands over your nose and mouth to create an air pocket that will give you air to breathe while you are waiting for rescue.

Once buried, more than 3/4 of avalanche victims die of suffocation. You have a 90% chance of survival if found within 15 minutes of of being buried in an avalanche. Most of the time, you cannot dig yourself out of an avalanche so you should relax and conserve oxygen if you can't free yourself.

In this scenario, two people were buried by the avalanche. The rest of the group searched for them starting where they were last seen. The group used their avalanche beacon to search for the people who were buried by making a zigzag pattern through the avalanche field since beacons only have a range of 20 yards. Once the beacon caught the signal, follow the signal to the beacon location then use a probe to find the exact location of the buried person.

Once the person is found, turn off their beacon so it won't interfere with finding the second person. Don't worry about the first person's injuries until the second person is found.

The second beacon was found three feet down so the group went down the hill three feet and dug in to find the victim (this takes less effort than digging down). Unfortunately, the beacon was found attached to the backpack of the victim which was ripped off during the avalanche.

Always wear your avalanche beacon on your person, not your gear!

When you see a rescue helicopter, signal them until they see you.

Set up a landing zone for the helicopter by clearing an area about 40' by 60'. Make sure the area is flat and has been cleared of large debris.

Rescue dogs were used to find the other person. Dogs can find people buried in six to 13 feet of snow and are much better at searching large areas than people.

Once the victims were loaded into the helicopter, directions were given to find the others who had been left behind.

This is good information for people who enjoy winter back country activities. I highly recommend watching the video.